In the past, normal blood pressure was stated to be ‘100 plus your age’, reflecting the fact that arteries harden with age, requiring the heart to pump harder to get blood around the body. But … normal may not be ideal. Current medical opinion advises that ideal blood pressure is less than 130 over 80. So what does this mean?
Blood pressure readings are a combination of two measurements. The upper number (Systolic) is the highest pressure against the arteries as the heart contracts -- ideally between 110 and 130. The lower number (Diastolic) is the pressure against the arteries as the heart relaxes and fills with blood -- ideally between 70 and 80.
Blood pressure does not stay the same all the time. It is affected by various things including body position, emotional stress, exercise and sleep. One isolated reading is not enough to determine whether blood pressure is ideal or not. It is only a concern if hypertensive at rest, because this means the heart is working hard to do its job and not resting between beats. Therefore it is best to measure when relaxed and sitting.
A few readings may be taken to get the true picture because many people ‘tense up’ during the procedure and nervous tension may temporarily boost blood pressure. If this happens with the doctor it is often called ‘white coat syndrome’! If a second blood pressure reading is needed, it is best to wait at least three minutes to allow the artery to resile between readings. If prone to White Coat Syndrome, a method of breathing while waiting may help to release tension and lower blood pressure. Breathe in to the count of 4. Hold to the count of 7; and breath out to the count of 8. Keep repeating.
One way to know whether there is a tendency toward hypertension is to be aware of the Mean Arterial Pressure -- a term used to describe an average blood pressure in an individual. To calculate it, multiply the diastolic by 2: add the systolic and divide the sum by 3. Normal Mean Arterial Pressure range is 70 to 110, with 80 being the ideal for health. If the Mean Arterial Pressure is persistently greater than 100 or diastolic greater than 90, blood pressure tablets may be indicated or medication may need to be adjusted. If readings are consistently high in the clinic, the doctor may recommend that the blood pressure be measured at home at least three times a day for a week. Alternatively, a 24-hour recording with a monitor that takes a reading every half hour during the day and every hour overnight may be used.
Hypertension usually produces no symptoms, so people may not realise they have it, therefore an annual blood pressure check is best. Blood pressure creeping up with age is unacceptable because over a period of time it can contribute to many illnesses, including: heart disease, kidney failure and stroke.
If drugs are prescribed, some may have different actions and side effects. Some cause swollen ankles, other may cause an irritable cough. Some are short-acting while others are long acting. ‘One size does not fit all’, and several different ones may need to be tried before a suitable one has been found.
Lifestyle factors are important in keeping blood pressure under control. Aim to maintain an ideal body weight by being physically active and eating a wide variety of fruit and vegetables along with a reduced salt diet. Alleviate stress factors as much as possible, limit alcohol intake and don’t smoke.
Sylvia Hutt RN, Our Saviour Lutheran Church, Aberfoyle Park, South Australia